Conventional videoconferencing systems comprise a number of end-points communicating real-time video, audio and/or data (often referred to as “duo video,” which is a feature that allows the codec to send two live video streams simultaneously, allowing the viewer to see the person speaking and additional content) streams over and between various networks such as WAN, LAN and circuit switched networks.
A number of videoconference systems residing at different sites may participate in the same conference, most often, through one or more MCU's (Multipoint Control Unit) performing, for example, switching and mixing functions to allow the audiovisual terminals to intercommunicate properly.
Video conferencing systems presently provide communication between at least two locations for allowing a video conference among participants situated at each station. Conventionally, the video conferencing arrangements are provided with one or more cameras. The outputs of those cameras are transmitted along with audio signals to a corresponding plurality of displays at a second location such that the participants at the first location are perceived to be present or face-to-face with participants at the second location.
Video conferencing systems are becoming increasingly common, especially in the desktop space. Landline telephones are exchanged with desktop video conferencing systems which may operate both as IP phones and video conferencing systems.
Each Video conferencing system has a unique identifier (or address) which is used when someone wishes to call a certain video conferencing system. For example, a video conferencing system operating on H.320 (ISDN) may have a unique phone number, and a Video conferencing system operating on H.323 (IP) may have a unique Uniform Resource Identifier (URI) or IP-address. This allows a user and his/her video conferencing system to be associated with one unique identifier, much like traditional telephone systems and telephone numbers.
However, the unique identifier is associated with the video conferencing system, so the user is only reachable at the physical location of the video conference system.
In an office environment this causes limitations in accessibility since people often are on the move, e.g. attending meetings, workgroups, etc. A user may also have several equally important work locations such as the office, the lab, common creative workspace, etc. Each location may have a video conference system. Hence, since each video conference system has its own unique identifier, and the caller usually does not know the physical location of the person he/she is trying to reach, the caller must either try to call all the locations he/she thinks the person may be or he/she must try to call back at a later stage.
Another problem with location-bound telecommunication equipment is the disturbance it may cause to immediate surroundings. Speech has been found to be the most annoying sound source in open plan offices, and the most distracting speech originates from the closest workstation. Since desktop video conferencing systems are more or less stationary devices, it is impossible to walk to a more private area to continue a call without first disconnecting the call and then reestablish the call at a different location.